Lawn trimmer



Nov. 1-3, 1951 ALLEN 2,574,947

LAWN TRIMMER Filed Aug. 16, 1948 gza I Jlli5 E 23 2 i 24 E INVENTQR. I6 5 EEMQZD 44 1. EN 5- BY 4 TTOEA/EY support for the cutting- Patented Nov. 13, r 1951 Erhard Allen, Dayton, Ohio: Helen Agnes Allen,

'executrix of said Erhard Allen, deceased, as-' signer to Helen Agnes Allen Application August 16, 1943', Serial No. 44,479

This invention relatesto alawn trimmer and one object of the invention is to provide a lawn trimmer ofa strong durable construction which can be produced at a relatively low cost and.

which can be easily manipulated.

A further object of the invention is to provide such a lawn trimmer with a; supporting structure or frame of simple'but strong construction which is supported bytraction wheels and providesfirm elements and their operating devices. i

A further object ofthe invention is to provide a frame which can be formed from a single piece of sheet metal at a low cost.

- A further object of the invention is to provide a lawn trimmer in which the cutter actuating cam is of such character and so arranged that it does not contact with or pick up dirt, grass cuttings or the like.

Other objects of the invention may appear the device is described in detail.

In the accompanying drawings Fig. 1 is a top plan view of a lawn trimmer embodying my invention; Fig. 2 is a side elevation partly in section on the line 2-2 of Fig. l'yFig. 3"isa front elevation of the lawn trimmer with the handle broken away; and Fig. 4 is a perspective view of a supporting frame.

In these drawings I have illustrated the preferred embodiment of my invention but'it is to be understood that the lawn trimmer as a whole,

as well as the several parts thereof, may take various forms without departing from the spirit of the invention.

' In the particular construction here illustrated the trimmer comprises a supporting frame 5 having a bottom or base member 6 and side members l which extend upwardly from the respective lateral edges of the base member and are preferably slightly inclined in a rearward direction. The side members are provided with alined bearings 8 in which is rotatably mounted a shaft 9, the end portions of which project outwardly beyond the side members 1. Traction wheels H] are drivingly connected with the shaft on the outer sides of the respective side members of the frame and preferably the wheels are rigidly secured to the respective end portions of the shaft. The wheels may be provided with traction surfaces of any suitable character and in the present instance each wheel is provided with a circumferential groove II and the flanges on the opposite sides of that groove are provided with spaced teeth 12 to resist the slipping of the wheel on the surface of the lawn. The wheels being 2 Claims. (01. 56-446 fin'ounted on the outer sides of the frame are spaced a substantial distance one from the other and thus strongly resist a tendency of the trimmerto 'tilt about an axis transverse to the shaft. The base member 6 of the frame projects forwardly beyond the side members of the frame a substantial distance and is provided at its forward end with forwardly extending and diverging cutter teeth I3. Thus the base member and its teeth constitute a stationary cutting element. The cutter teeth may, if desired, be formed integral with the base member but preferably they are formed separately therefrom and rigidly secured thereto, as by rivets Hi the upper ends of which are flush with the upper surface of the base member. Connected with the base member for oscillating movement with relation thereto is a cutting element lli which, in the form shown, comprises an elongate body portion having rigidly secured to the forward end thereof, and in the present instance formed integral therewith, a plurality of cutter teeth It arranged to cooperate with the cutterteeth 13 of the base member. This movable cutting member may be arranged in any suitable relation to the station.- ary cutting element, or base member 15. Pref-.- erably it is arranged above and in supporting engagement with the stationary cutting element and is pivotally connected therewith for movement about a vertical axis between the ends thereof. The movable cutting element may be connected with the stationary cutting element man suitable manner and in the arrangement shown a pivot pin, such as a bolt l'l, extends through alined openings in the two cutting elements andis retained therein by a nut 18. The bolt is of a length somewhat greater than the combined thickness of the two elements and. a coil spring I9 is interposed between the head of the bolt and the movable cutting element to press the cutter teeth of the latter into firm engagement with the cutter teeth of the stationafy cutting element. oscillatory movement is imparted to the movable cutting element by cam means actuated by the traction wheels. The cam means may take various forms and the cutting element may be connected therewith in any suitable manner. Preferably the cutting element [5 is provided in the rear of its pivotal axis with an upwardly extending stud 20, here shown as arranged directly below the shaft 9 and provided with an antifriction roller 2|. The cam is preferably of the rotatable type having a circumferential cam groove into which the stud 20 extends. In the present instance the cam is supporting 'frame,

the upper-portions of-the sidelmembers 110f the l frame extend inwardly lasr-shown at-lland are provided with upwardly extending: opposed .por-

shown at 22 as comprising two spirally spaced parts 23 and 24 rigidly secured to the shaft 9, as by pins 25, and provided with opposed cam surfaces forming between the same a circumferential cam groove 26 into which the stud l1 extends. T'he cam may be provided with any desired number of lobes to cause any desired number of cutting movements-pf the: oscillating cutting element upon-each rotationof the cam.

It will be noted that the cam is of a diameter substantially less than the diameters of the tradtion wheels and inasmuch as the cam and the wheels rotate about the same axis this results in that surface of the cam rwhich-islowermost being spaced above the surface ofrtheilawn such a distance that it will not have contact with the lawn and will not pick updirt, grass cuttings or the like, which otherwise might enter the same and interfere with the proper operation-.101 athe trimmer.

.The trimmer maybe. propelled: in any. suitable manner but usually itwis :manually propelleduby ahandle which: is preferably connectedwith the In the construction shown tions 28, which-in the, present. instance are rear- -wardly-- inclined. The opposed. portions 72B ofthe side members .are 3 preferably curved I to provide the samewith channel'std receive thezlower end portionof a: propelling handle. and arerigidly secured tosthehandlalasaby means of a pin .3 0.

Thus the upper ends-of .theside members are rigidly connected one with 1 theother and with the handle. It willbe apparentthat the frame is base member between and rigidly connected with the'lower portions of .said side members and extending forwardly a substantial distance beyond said side members, the upperpportions of said side members having inwardly extending parts shaped to receive and support between them the .end portion of a propelling handle, a shaft rotatably supported in said bearings, ground wheels drivingly connected with said shaft on the outer sides of the respective side members of said frame, a cam member rigidly secured to said shaft between said side members, stationary cutter teeth secured to and diverging forwardly from the forward end of said base member, and an Lelongate cutting element mounted:between its 'ends on saidbase membehfor movement about a vertical axis, having at its forward end cutting teeth to cooperate with said stationary cutting teeth-and having at its rear end a part engaging and actuated by said cam to impart oscillatory =movementthereto about said vertical axis.

2i*l.'-n-=a lawn trimmer, a frame comprising up- 'wariily and rearwardly inclined side members :having ralinedzbearings, and a horizontal base member rigidly connecting the lower portions of sa'idside members one with the other, a shaft journaled in said bearings, ground Wheels rigidly secured to saidshaftron the: outer sides of the :respective side members and extending below said base i member, :sa'i-dtzbase. member extending 'fiorwardly :a substantial distance beyond said wheels, forwardly extending laterally spaced uittingteethisecnredto'rthezforward end of said base 'membereanielongate' cutting element mount- :ed'ibetweenits ends on said base memberfor :movement about :a-verticai taxis adjacent the 'sfonwardilower'corner ptsaid side members and having in the rear of said axislancaml engaging :part,; a cam rigidly 'secureditozsaid shaft -between said side members and thavinga periferal cam groove to receive said rcamuengagingpart of said elongate element, and a propelling handle connected -withxsaid 1 frame.

ERHARD ALLEN.

REFERENCES GITED "The' foilowing'references are of record in the file of this patent:

'UNITED STATES PATENTS .Number Name Date :Re.113;463- "Karcher' Aug. 27, 1191-2 63.;578 ;Doudna.,. Oct. 20,1861 .-'12,722: Cooke. s.,... -Dec. 31, 1.867 208,355 Wright M. .,Sept. 4, 1878 1370, 271 Fitzgerald V Oct.4. 1887 387-;461 'Card ,;May-12, 1908 953,541 Montgomeryrpflup. Mar. 29, 1910 1,057,015 .Stover A Mar. 25, 1913 01336031 Clark May 24, 1932 2,025,537 Tauber Dec. 24, 1935 ..2-,151,5113 Wuitynecl:v ;Mar. 21, 1939 

